Mobile machines such as haul trucks, motor graders, water trucks, and other large equipment are concurrently utilized at a common worksite to accomplish a variety of tasks. These machines can be large, difficult to operate, heavy, and slow to respond. In addition, the travel routes of the machines can intersect with (e.g., coincide with and/or or partially overlap with) each other. Accordingly, it is important to control the traffic pattern of these machines in order to reduce the opportunity for collision, machine damage, and deadlock to occur. This may be particularly important when the machines are autonomously and/or remotely controlled.
One attempt at traffic control for unmanned vehicles is described in U.S. Pat. No. 8,566,009 that issued to Ozaki et al. on Oct. 22, 2013 (“the '009 patent”). Specifically, the '009 patent describes a travel control apparatus operable to determine travel routes for each of the unmanned vehicles. During operation, each vehicle will request a travel route reservation from a current location to a desired end point. The travel control apparatus will then determine if the requested reservation intersects with an already reserved route of another vehicle. If an intersection exists, the travel control apparatus will make a reservation corresponding to only a portion of the requested route, up to a terminal edge of the already reserved route. The travel control apparatus will then determine if deadlock exists between the two reserved routes. If deadlock exists, the travel control apparatus will release the reservation of the corresponding vehicle having a lower travel priority.
Although the travel control apparatus of the '009 patent may help avoid collision and deadlock, it may still be less than optimal. In particular, the travel control apparatus may be inefficient and wasteful by reserving routes for individual vehicles that have the potential for deadlock. In some instances, the travel control apparatus may have to reserve and release routes multiple times before picking a route that is acceptable.
The disclosed traffic control system is directed to overcoming one or more of the problems set forth above and/or other problems of the prior art.